(9) Where the harm was caused by more than one activity and could be reasonably traced to each one of them, but could not be separated with any degree of certainty, liability could either be joint and several or could be equitably apportioned.
9) Cuando el daño fuera causado por más de una actividad y pudiera razonablemente ser vinculado a cada una de ellas sin que fuese posible separarlas con certeza, la responsabilidad podría ser solidaria o se podría repartir equitativamente.